Just a quick report that DVR seems to run just fine on Mac Os X Mavericks.
I have an older Mac which I was fed up of running slowly, so I downgraded to Mavericks. It’s pretty zippy now and best of all Channels DVR seems to run fine - 4 days of uptime so far with no problems to report.
Will update this thread if future updates prove to be a problem with this aged OS.